2021 RedEye . . . no boost all of a sudden? Pulley seems fine, and NO CELs ????

[cobrakid]

hey guys,

at my favorite race of the year Cecil HHP day....last weekend. Sticky track, cool temps expecting best pass ever. ..then NOPE! NO BOOST!

My car's second pass.... normal burnout, felt like I left the line in 3rd gear :-( . . .then about 80 ft out took off like normal.
Ran a 10.42@136 with a dismal 1.69 60 ft. Should have literally been a 1.4 60ft, 9.90@138ish.

On return road, car felt like it had 400 hp, and noticed NO BOOST at all. No whine, no rev blower noise, no boost on gauge.
....got to parking spot, though damn, blower belt broke or something. Popped hood, no, factory green belt still there, pulley looked
100% fine. When idling, no noise, pulley straight and true... cover still on it, no goo coming out, not backed up to snout, all looked perfectly normal.
also, NO codes, no CELs, ran vehicle diagnostics, and nothing showing on dash or other-wise.

Pulled belt off blower... pulley had resistance both ways, not buckling (for lack of better word) turning straight.... nothing seeming or feeling bad. (?)
Decided to pull off throttle body sensor, then By-Pass sensor connectors 1 at a time...restart and checked all. Each time dash showed "service Throttle body"
or similar message, but as soon as they were both hooked back up and re-started... all seemed fine, no lights, no dash messages nothing. but STILL NO BOOST.
(while each was disconnected, car would not rev while depressing gas pedal as normal I believe)

Disconnected the battery..... re-hooked it back after 10 minutes.... lost all SRT functions as normal... then, ACTUALLY drove out of track on a 5 mile ride hoping
everything might kick back in. NOPE, done for the day, loaded up and left later on. Got home, to back off trailer.... all SRT functions and dash screens correct
& restored . . . . just still NO BOOST, no CELs... no anything.

I feel like the pulley is fine.... and maybe the By-Pass is stuck open or something as it doesn't even try to whine or boost when idle revving it.

WHAT am I supposed to try other than taking it to a dealer...etc....

I would order a new by-pass assembly to simply bolt on if I thought that would quickly and easily fix it. (?)

Should I try disconnecting the batter over night, and try again ?

Any thoughts advise, anything?

--thanks in advance . . . car has less than 3900 miles on it....

 

[Hunter]

hey guys,

at my favorite race of the year Cecil HHP day....last weekend. Sticky track, cool temps expecting best pass ever. ..then NOPE! NO BOOST!

My car's second pass.... normal burnout, felt like I left the line in 3rd gear :-( . . .then about 80 ft out took off like normal.
Ran a 10.42@136 with a dismal 1.69 60 ft. Should have literally been a 1.4 60ft, 9.90@138ish.

On return road, car felt like it had 400 hp, and noticed NO BOOST at all. No whine, no rev blower noise, no boost on gauge.
....got to parking spot, though damn, blower belt broke or something. Popped hood, no, factory green belt still there, pulley looked
100% fine. When idling, no noise, pulley straight and true... cover still on it, no goo coming out, not backed up to snout, all looked perfectly normal.
also, NO codes, no CELs, ran vehicle diagnostics, and nothing showing on dash or other-wise.

Pulled belt off blower... pulley had resistance both ways, not buckling (for lack of better word) turning straight.... nothing seeming or feeling bad. (?)
Decided to pull off throttle body sensor, then By-Pass sensor connectors 1 at a time...restart and checked all. Each time dash showed "service Throttle body"
or similar message, but as soon as they were both hooked back up and re-started... all seemed fine, no lights, no dash messages nothing. but STILL NO BOOST.
(while each was disconnected, car would not rev while depressing gas pedal as normal I believe)

Disconnected the battery..... re-hooked it back after 10 minutes.... lost all SRT functions as normal... then, ACTUALLY drove out of track on a 5 mile ride hoping
everything might kick back in. NOPE, done for the day, loaded up and left later on. Got home, to back off trailer.... all SRT functions and dash screens correct
& restored . . . . just still NO BOOST, no CELs... no anything.

I feel like the pulley is fine.... and maybe the By-Pass is stuck open or something as it doesn't even try to whine or boost when idle revving it.

WHAT am I supposed to try other than taking it to a dealer...etc....

I would order a new by-pass assembly to simply bolt on if I thought that would quickly and easily fix it. (?)

Should I try disconnecting the batter over night, and try again ?

Any thoughts advise, anything?

--thanks in advance . . . car has less than 3900 miles on it....

Hopefully someone has input.
That sucks

 

[cobrakid]

basically I am asking is there an EASY WAY to check if the By-Pass valve is working, or sticking open?

 

[1971demon]

basically I am asking is there an EASY WAY to check if the By-Pass valve is working, or sticking open?

Somebody here has to know....

 

[Speedy!]

A data log will tell you.

 

[ostmike]

I don't see any modifications listed other than the green belt. Regardless I suspect the car has an aftermarket tune and your are experiencing a tuning related issue. As Speedy indicated a datalog will show if the bypass is operating.
However, if you have a throttle code you will not have normal bypass functionality. You will need to fix that issue before proceeding.

 

[Billet Train]

I had a litens 2.72 pulley go bad just 2 months ago. Same symptoms, no boost, no cels. Took the belt off, rotors spun freely, put a towel in the rotors and bingo, I could turn the pulley with my hand. Replaced it with a Grip Tec pulley problem solved.

 

[GNBRETT]

Sounds like pulley failure had that on my Trackhawk couple years ago switched to Griptech and the AAD pulley tensioner to prevent further slip. It wont show a code.

 

[cobrakid]

..update...and weird; . . still lost a great day of racing.
RETURNED car to stock (reverted to OEM) via Direct Connection tuner.... disconnected battery.
UPDATED the tuner online.... (stated 6 updates) . ... and reloaded in my car. Problem solved!
Per dash pulling lots of boost correctly and burns up the drag radials all the way through even while rolling.
The car won't hook on the street no matter what I do, so no real to test under load/dead hook. (to check shift points etc)
Final time runs will be this weekend at MIR on Sunday. (which is crappy on a Sunday) LOL
I will post results ..... 9s or selling!

 

[SilverBillet]

Thanks for the update @cobrakid. I’m sure some of us were following this.